RFC 1566 Mail Monitoring MIB January 19941. Introduction
This memo defines a portion of the Management Information Base (MIB)
for use with network management protocols in the Internet community.
In particular, this memo extends the basic Network Services
Monitoring MIB [5] to allow monitoring of Message Transfer Agents
(MTAs). It may also be used to monitor MTA components within
gateways.
2. The SNMPv2 Network Management Framework
The SNMPv2 Network Management Framework consists of four major
components. They are:
o RFC 1442 [1] which defines the SMI, the mechanisms used for
describing and naming objects for the purpose of management.
o STD 17, RFC 1213 [2] defines MIB-II, the core set of managed
objects for the Internet suite of protocols.
o RFC 1445 [3] which defines the administrative and other
architectural aspects of the framework.
o RFC 1448 [4] which defines the protocol used for network
access to managed objects.
The Framework permits new objects to be defined for the purpose of
experimentation and evaluation.
2.1 Object Definitions
Managed objects are accessed via a virtual information store, termed
the Management Information Base or MIB. Objects in the MIB are
defined using the subset of Abstract Syntax Notation One (ASN.1)
defined in the SMI. In particular, each object type is named by an
OBJECT IDENTIFIER, an administratively assigned name. The object
type together with an object instance serves to uniquely identify a
specific instantiation of the object. For human convenience, we
often use a textual string, termed the descriptor, to refer to the
object type.
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RFC 1566 Mail Monitoring MIB January 19943. Message Flow Model
A general model of message flow inside an MTA has to be presented
before a MIB can be described. Generally speaking, message flow
occurs in four steps:
(1) Messages are received by the MTA from User Agents, Message
Stores, other MTAs, and gateways.
(2) The "next hop" for the each message is determined. This is
simply the destination the message is to be transmitted to;
it may or may not be the final destination of the message.
Multiple "next hops" may exist for a single message (as a
result of either having multiple recipients or distribution
list expansion); this may make it necessary to duplicate
messages.
(3) Messages are converted into the format that's appropriate
for the next hop.
(4) Messages are transmitted to the appropriate destination,
which may be a User Agent, Message Store, another MTA, or
gateway.
Storage of messages in the MTA occurs at some point during this
process. However, it is important to note that storage may occur at
different and possibly even multiple points during this process. For
example, some MTAs expand messages into multiple copies as they are
received. In this case (1), (2), and (3) may all occur prior to
storage. Other MTAs store messages precisely as they are received
and perform all expansions and conversions during retransmission
processing. So here only (1) occurs prior to storage. This leads to
situations where, in general, a measurement of messages received may
not equal a measurement of messages in store, or a measurement of
messages stored may not equal a measurement of messages
retransmitted, or both.
4. MTA Objects
If there are one or more MTAs on the host, the following mta group
may be used to monitor them. Any number of the MTAs on a host may be
monitored. Each MTA is dealt with as a separate application and has
its own applTable entry in the Network Services Monitoring MIB.
The MIB described in this document covers only the portion which is
specific to the monitoring of MTAs. The network service related part
of the MIB is covered in a separate document [5].
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RFC 1566 Mail Monitoring MIB January 1994
mtaReceivedVolume OBJECT-TYPE
SYNTAX Counter32
UNITS "K-octets"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total volume of messages received since MTA
initialization, measured in kilo-octets. This volume should
include all transferred data that is logically above the mail
transport protocol level. For example, an SMTP-based MTA
should use the number of kilo-octets in the message header
and body, while an X.400-based MTA should use the number of
kilo-octets of P2 data."
::= {mtaEntry 4}
mtaStoredVolume OBJECT-TYPE
SYNTAX Gauge32
UNITS "K-octets"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total volume of messages currently stored in the MTA,
measured in kilo-octets. This volume should include all
stored data that is logically above the mail transport
protocol level. For example, an SMTP-based MTA should
use the number of kilo-octets in the message header and
body, while an X.400-based MTA would use the number of
kilo-octets of P2 data."
::= {mtaEntry 5}
mtaTransmittedVolume OBJECT-TYPE
SYNTAX Counter32
UNITS "K-octets"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total volume of messages transmitted since MTA
initialization, measured in kilo-octets. This volume should
include all transferred data that is logically above the mail
transport protocol level. For example, an SMTP-based MTA
should use the number of kilo-octets in the message header
and body, while an X.400-based MTA should use the number of
kilo-octets of P2 data."
::= {mtaEntry 6}
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RFC 1566 Mail Monitoring MIB January 1994
mtaReceivedRecipients OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of recipients specified in all messages
received since MTA initialization. Recipients this MTA
had no responsibility for should not be counted even if
information about such recipients is available."
::= {mtaEntry 7}
mtaStoredRecipients OBJECT-TYPE
SYNTAX Gauge32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of recipients specified in all messages
currently stored in the MTA. Recipients this MTA had no
responsibility for should not be counted."
::= {mtaEntry 8}
mtaTransmittedRecipients OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of recipients specified in all messages
transmitted since MTA initialization. Recipients this MTA
had no responsibility for should not be counted."
::= {mtaEntry 9}
-- MTAs typically group inbound reception, queue storage, and
-- outbound transmission in some way. In the most extreme case
-- information will be maintained for each different entity that
-- receives messages and for each entity the MTA stores messages for
-- and delivers messages to. Other MTAs may elect to treat all
-- reception equally, all queue storage equally, all deliveries
-- equally, or some combination of this.
-- In any case, a grouping abstraction is an extremely useful for
-- breaking down the activities of an MTA. For purposes of labelling
-- this will be called a "group" in this MIB.
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RFC 1566 Mail Monitoring MIB January 1994
-- Each group contains all the variables needed to monitor all aspects
-- of an MTA's operation. However, the fact that all groups contain
-- all possible variables does not imply that all groups must use all
-- possible variables. For example, a single group might be used to
-- monitor only one kind of event (inbound processing, outbound
-- processing, or storage). In this sort of configuration all unused
-- counters would be inaccessible; e.g., returning either a
-- noSuchName error (for an SNMPv1 get), or a noSuchInstance
-- exception (for an SNMPv2 get).
-- Groups are not necessarily mutually exclusive. A given event may
-- be recorded by more than one group, a message may be seen as
-- stored by more than one group, and so on. Groups should be all
-- inclusive, however: if groups are implemented all aspects of an
-- MTA's operation should be registered in at least one group. This
-- freedom lets implementors use different sets of groups to
-- provide differents "views" of an MTA.
-- The possibility of overlap between groups means that summing
-- variables across groups may not produce values equal to those in
-- the mtaTable. mtaTable should always provide accurate information
-- about the MTA as a whole.
-- The term "channel" is often used in MTA implementations; channels
-- are usually, but not always, equivalent to a group. However,
-- this MIB does not use the term "channel" because there is no
-- requirement that an MTA supporting this MIB has to map its
-- "channel" abstraction one-to-one onto the MIB's group abstration.
mtaGroupTable OBJECT-TYPE
SYNTAX SEQUENCE OF MtaGroupEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The table holding information specific to each MTA group."
::= {mta 2}
mtaGroupEntry OBJECT-TYPE
SYNTAX MtaGroupEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The entry associated with each MTA group."
INDEX {applIndex, mtaGroupIndex}
::= {mtaGroupTable 1}
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RFC 1566 Mail Monitoring MIB January 1994
OBJECT IDENTIFIER,
mtaGroupName
DisplayString
}
mtaGroupIndex OBJECT-TYPE
SYNTAX INTEGER (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The index associated with a group for a given MTA."
::= {mtaGroupEntry 1}
mtaGroupReceivedMessages OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of messages received to this group since MTA
initialization."
::= {mtaGroupEntry 2}
mtaGroupRejectedMessages OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of messages rejected by this group since MTA
initialization."
::= {mtaGroupEntry 3}
mtaGroupStoredMessages OBJECT-TYPE
SYNTAX Gauge32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of messages currently stored in this
group's queue."
::= {mtaGroupEntry 4}
mtaGroupTransmittedMessages OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of messages transmitted by this group since MTA
initialization."
::= {mtaGroupEntry 5}
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RFC 1566 Mail Monitoring MIB January 1994
mtaGroupReceivedVolume OBJECT-TYPE
SYNTAX Counter32
UNITS "K-octets"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total volume of messages received to this group since
MTA initialization, measured in kilo-octets. This volume
should include all transferred data that is logically above
the mail transport protocol level. For example, an
SMTP-based MTA should use the number of kilo-octets in the
message header and body, while an X.400-based MTA should use
the number of kilo-octets of P2 data."
::= {mtaGroupEntry 6}
mtaGroupStoredVolume OBJECT-TYPE
SYNTAX Gauge32
UNITS "K-octets"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total volume of messages currently stored in this
group's queue, measured in kilo-octets. This volume should
include all stored data that is logically above the mail
transport protocol level. For example, an SMTP-based
MTA should use the number of kilo-octets in the message
header and body, while an X.400-based MTA would use the
number of kilo-octets of P2 data."
::= {mtaGroupEntry 7}
mtaGroupTransmittedVolume OBJECT-TYPE
SYNTAX Counter32
UNITS "K-octets"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total volume of messages transmitted by this group
since MTA initialization, measured in kilo-octets. This
volume should include all transferred data that is logically
above the mail transport protocol level. For example, an
SMTP-based MTA should use the number of kilo-octets in the
message header and body, while an X.400-based MTA should use
the number of kilo-octets of P2 data."
::= {mtaGroupEntry 8}
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RFC 1566 Mail Monitoring MIB January 1994
mtaGroupReceivedRecipients OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of recipients specified in all messages
received to this group since MTA initialization.
Recipients this MTA had no responsibility for should not
be counted."
::= {mtaGroupEntry 9}
mtaGroupStoredRecipients OBJECT-TYPE
SYNTAX Gauge32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of recipients specified in all messages
currently stored in this group's queue. Recipients this
MTA had no responsibility for should not be counted."
::= {mtaGroupEntry 10}
mtaGroupTransmittedRecipients OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of recipients specified in all messages
transmitted by this group since MTA initialization.
Recipients this MTA had no responsibility for should not
be counted."
::= {mtaGroupEntry 11}
mtaGroupOldestMessageStored OBJECT-TYPE
SYNTAX TimeInterval
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Time since the oldest message in this group's queue was
placed in the queue."
::= {mtaGroupEntry 12}
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RFC 1566 Mail Monitoring MIB January 1994
mtaGroupInboundAssociations OBJECT-TYPE
SYNTAX Gauge32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of current associations to the group, where the
group is the responder."
::= {mtaGroupEntry 13}
mtaGroupOutboundAssociations OBJECT-TYPE
SYNTAX Gauge32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The number of current associations to the group, where the
group is the initiator."
::= {mtaGroupEntry 14}
mtaGroupAccumulatedInboundAssociations OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of associations to the group since MTA
initialization, where the group is the responder."
::= {mtaGroupEntry 15}
mtaGroupAccumulatedOutboundAssociations OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of associations from the group since MTA
initialization, where the group was the initiator."
::= {mtaGroupEntry 16}
mtaGroupLastInboundActivity OBJECT-TYPE
SYNTAX TimeInterval
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Time since the last time that this group had an active
inbound association for purposes of message reception."
::= {mtaGroupEntry 17}
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RFC 1566 Mail Monitoring MIB January 1994
mtaGroupLastOutboundActivity OBJECT-TYPE
SYNTAX TimeInterval
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Time since the last time that this group had an
outbound association for purposes of message delivery."
::= {mtaGroupEntry 18}
mtaGroupRejectedInboundAssociations OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of inbound associations the group has
rejected, since MTA initialization."
::= {mtaGroupEntry 19}
mtaGroupFailedOutboundAssociations OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number associations where the group was the
initiator and association establishment has failed,
since MTA initialization."
::= {mtaGroupEntry 20}
mtaGroupInboundRejectionReason OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The failure reason, if any, for the last association this
group refused to respond to. An empty string indicates that
the last attempt was successful. If no association attempt
has been made since the MTA was initializaed the value
should be 'never'."
::= {mtaGroupEntry 21}
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RFC 1566 Mail Monitoring MIB January 1994
mtaGroupOutboundConnectFailureReason OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The failure reason, if any, for the last association attempt
this group initiated. An empty string indicates that the last
attempt was successful. If no association attempt has been
made since the MTA was initialized the value should be
'never'."
::= {mtaGroupEntry 22}
mtaGroupScheduledRetry OBJECT-TYPE
SYNTAX TimeInterval
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The time when this group is scheduled to next attempt to
make an association."
::= {mtaGroupEntry 23}
mtaGroupMailProtocol OBJECT-TYPE
SYNTAX OBJECT IDENTIFIER
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"An identification of the protocol being used by this group.
For an group employing OSI protocols, this will be the
Application Context. For Internet applications, the IANA
maintains a registry of the OIDs which correspond to well-known
message transfer protocols. If the application protocol is
not listed in the registry, an OID value of the form
{applTCPProtoID port} or {applUDProtoID port} are used for
TCP-based and UDP-based protocols, respectively. In either
case 'port' corresponds to the primary port number being
used by the group. applTCPProtoID and applUDPProtoID are
defined in [5]."
::= {mtaGroupEntry 24}
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RFC 1566 Mail Monitoring MIB January 1994
mtaGroupName OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"A descriptive name for the group. If this group connects to
a single remote MTA this should be the name of that MTA. If
this in turn is an Internet MTA this should be the domain name.
For an OSI MTA it should be the string encoded distinguished
name of the managed object using the format defined in RFC-1485.
For X.400(1984) MTAs which do not have a Distinguished Name,
the RFC-1327 syntax 'mta in globalid' should be used."
::= {mtaGroupEntry 25}
mtaGroupAssociationTable OBJECT-TYPE
SYNTAX SEQUENCE OF MtaGroupAssociationEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The table holding information regarding the associations
for each MTA group."
::= {mta 3}
mtaGroupAssociationEntry OBJECT-TYPE
SYNTAX MtaGroupAssociationEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The entry holding information regarding the associations
for each MTA group."
INDEX {applIndex, mtaGroupIndex, mtaGroupAssociationIndex}
::= {mtaGroupAssociationTable 1}
MtaGroupAssociationEntry ::= SEQUENCE {
mtaGroupAssociationIndex
INTEGER
}
mtaGroupAssociationIndex OBJECT-TYPE
SYNTAX INTEGER (1..2147483647)
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Reference into association table to allow correlation of
this group's active associations with the association table."
::= {mtaGroupAssociationEntry 1}
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